Laminar Flow and cooling

Aptera Community Aptera Discussions Laminar Flow and cooling

Aptera Community Aptera Discussions Laminar Flow and cooling

  • Laminar Flow and cooling

     Richard Palmisano updated 1 month ago 7 Members · 20 Posts
  • Richard Palmisano

    Member
    September 21, 2021 at 7:46 am

    Doing a little digging, I found some data that suggests that laminar flow, which is amazing for aerodynamics, is not great for heat dissipation. When laminar flow is achieved, a boundary layer is created and that boundary layer is insulative.

    This means that using the exterior panels as radiators might not be the most efficient means of dissipating or gaining heat. This is a huge deal for southern climates with high humidity.

    Can we get a little more information related to the climate system?

  • Peter Jorgensen

    Member
    September 21, 2021 at 7:54 am
    • Richard Palmisano

      Member
      September 21, 2021 at 8:02 am

      Peter, at 30,000 feet the skin of the aircraft is subjected to -48 deg F (avg), I think that’s fantastic for aviation and you can reject as much heat as you literally want.

      At sea level, with 80-90% humidity and 95 deg F surface temps, I am more curious how effective this will be.

  • kerbe2705

    Member
    September 21, 2021 at 8:28 am

    In your last line did you mean “cooling” or “climate”? I understand “climate” in reference to HVAC, not motor, battery and power electronics cooling…

  • John Malcom

    Member
    September 21, 2021 at 8:56 am

    I think the Aptera engineers are pretty astute at doing research and experimentation to determine the best solution for engineering the Aptera for a range of environmental conditions. They have a mix of engineering skills including automotive and aerospace and collaborate in a multidisciplinary fashion. Of course, the proof of any engineering solution is in operational testing. I believe they will do thorough testing and remediation if necessary so that my Aptera will function well in the Florida heat an humidity.

    • Richard Palmisano

      Member
      September 21, 2021 at 12:07 pm

      Climate, cooling, etc.

      If you look at other EVs, there is a multi-junction valve (Tesla octovalve for instance) that diverts cooling and heating respectively to batteries and climate system.

      John, I’m not saying that they do not have a plan, have engineered a solution, but it’s a new technology in regards to being applied to the automotive space. As someone who want’s to be an initial adopter, with a low allocation number, I have questions about the systems of the vehicle.

      This isn’t confrontational, it’s not saying the engineers are dolts, it’s not saying it won’t work.

      I have seen most of the information presented and understand the approach using the skin as a radiator, but I have also researched the viability of laminar flow in relation to heat/cooling transfer and what’s good for aero is not necessarily good for heat/cooling transfer.

    • Richard Palmisano

      Member
      September 21, 2021 at 12:38 pm

      John, I have no doubt that the engineers have researched this and have a solution. Can we get some information related to this though?

      I am not saying it won’t work, I’m not saying they haven’t worked it out, nor am I saying they are dolts. I am saying laminar flow is not ideal for heat gain/dissipation. Turbulent flow is better at this.

      I as an early adopter with a low reservation number have questions. I have watched all of the provided information from Aptera, and I like their presentations. It’s getting close to ‘nut’ time though. Rather than a ‘hey they got this’ response, is there someone with actual information related to the systems and how they will perform?

      • John Malcom

        Member
        September 21, 2021 at 1:36 pm

        Richard, I did not take it as confrontational. Sounds like you might be a heat transfer person with legitimate concerns as you will get an early production model. There is a body makers segment coming up. Perhaps we can get some discussion on the cooling topic included. There was none in the makers presentation on batteries

  • Joshua Rosen

    Member
    September 21, 2021 at 1:12 pm

    It would be a fascinating topic for a webinar. However that will have to wait until they’ve filed all of their patents and starting shipping the car. This is core IP for Aptera, they have to be careful to protect it.

    • Richard Palmisano

      Member
      September 21, 2021 at 2:13 pm

      I agree. I do understand that this is IP territory, but it is a huge concern for my location in NE Florida. AC is king here…😎

  • Christopher May

    Member
    September 21, 2021 at 1:56 pm

    Imagine, if this entire time, they ran simulations with it set to a default cruising altitude for airliners. How big of a D’OH moment would that be? XD

    • Richard Palmisano

      Member
      September 21, 2021 at 2:12 pm

      LOL…I am not saying that this is the case at all!

    • John Malcom

      Member
      September 22, 2021 at 12:20 pm

      A big OOOPS for sure with a lot of hand waving……..

  • John Malcom

    Member
    September 21, 2021 at 2:14 pm

    Joshua, I am not sure you are in a position to make such a statement as there is no information available To us on what Aptera considers protectable IP and what if anything they would want to submit a patent for. It may not be patentable as “Knowledge of it (The concept) has been known to the public” one of the disqualifying factors for a patent. Or they may have applied already which would not make sense as they are in the early stages of prototype development.

    At any rate it does not hurt to make an inquiry. This is for an early adopter with some knowledge of heat transfer mechanics with a legitimate concern.

    If they have a reason Not to answer fine

    • Joshua Rosen

      Member
      September 22, 2021 at 6:11 am

      John

      I’ve spent my career on the forefronts of technology, in my case high performance computing, and I have a number of patents. Most patents aren’t fundamental, companies get them to fill out their patent portfolios, and a very few are and those are the important ones. Cooling is outside of my area of expertise so I don’t know what’s patentable in this field and what’s not but as someone who’s been through the process Aptera’s skin cooling sure feels like it could be a fundamental invention. I have no doubt that they’ve already filed patents in this area but there may be follow on patents that haven’t been filed. In patent law you lose the right to patent something if it’s been publicly disclosed. You can show it to an outsider under an NDA, that’s not considered public, but if you make any public disclosures it goes into the public domain. That’s what I was getting at by saying that they have to have all of their IP ducks in a row before they can do a webinar. I also mentioned not doing it before they’ve shipped the vehicle. This is a practical consideration not a legal one. As soon as the car is available the Chinese are going to reverse engineer it. I’ve done business in China and it has not been a happy experience, I’ve also experienced attacks from China on my source control server. The patents will protect them in the West where patent laws are strong but in China, where IP rights are not respected, the best strategy is to keep information private until it’s no longer possible, i.e. until the product is available.

      My undergraduate degree was in physics so I’d find a detailed explanation of their cooling technique fascinating and I look forward to a webinar on the subject. However I wouldn’t expect it until they’ve filed all of the patents that that they are going to file.

      • John Malcom

        Member
        September 22, 2021 at 12:13 pm

        I am not sure why this post was directed at me, or what this has to do with answering Richards question. I am also not sure what our credential posturing achieves on the forum. But, here is mine.

        My first two degrees were in physics and I did my post doc work at the IBM Thomas J. Watson Research Lab in Yorktown Heights and Cambridge MA, probably close to where you live. As you may know, researchers at the IBM Labs are not allowed to hold patents, IBM is the filer and owner. I left IBM as a Senior Vice President of R&D at the time when the Federal Systems Division was sold to Lockheed Martin and went on to be a Senior Vice President of Technology at Citi Bank. I lived and worked in China for seven years so am very familiar with their enterprise culture and in fact admire their model and wish we could match it. My wife is PRC and currently a professor of math at the University of Florida. She is PRC Chinese to the core and always a reminder of their culture.

        I don’t think that Aptera management are neophytes with regard to China business. The original Aptera IP was sold to a Chinese company and Aptera Founders got it back. Also, the CFO has a Chinese background and, based on her credentials, quite an astute business person. I do not believe that China will be able to take unfair advantage of Aptera.

        I certainly support your concern about protecting Aptera IP. But I trust Aptera management to balance protection with the transparency they have shown about sharing their technology, allying enthusiasts concerns, and answering questions.

        So let’s trust Aptera management to manage their business and make the decisions on how to respond to questions. We have different backgrounds and our experience is not necessarily applicable to their business which in itself (Aside from the vehicle) is innovative and breaking ground.

        Feichang ganxie nin

        • Joshua Rosen

          Member
          September 22, 2021 at 1:12 pm

          John

          My original comment on this tread wasn’t directed at you, I was just trying to explain to everyone else why they might not be able to do a webinar at this point. The last comment was a direct response to your statement that I wasn’t in a position to make such a statement. I was just clarifying why I thought that it might not be possible to share this information at this time. Of course it’s up to Aptera’s management to make that decision. I’m sure they have first class IP attorneys and if everything is already squared away I’d be fascinated to hear the details of what they are doing in this area. We seem to have gotten off on the wrong foot with each other, I hope we can get back to a less confrontational relationship.

          • Richard Palmisano

            Member
            September 23, 2021 at 5:06 am

            Joshua, your summation related to NDA and patents reminds me of Sandy Munro and his podcast. He has been asked many a question related to Aptera and other companies that he is working with and he quickly will say something to the effect, “ummm, yeah can’t talk about that one…NDA…lets move on”.

  • Carl Knapp

    Member
    September 21, 2021 at 5:17 pm

    Your concern about the heat transfer skin effect is valid. I asked them 7 months ago during one open meeting and they responded they have addressed this in their design. I would hope so living in AZ where the temps hit 120F. But at least it is a dry heat.😀

    • Richard Palmisano

      Member
      September 22, 2021 at 4:44 am

      Carl, dry, moist (love that word) heat, doesn’t matter. The fact also that we will be placing our vehicles in direct sunlight with solar thermal gain to gather miles adds to the question. Typically I search for a shaded spot here in NE Florida now to keep the radiant energy from making the cabin unbearable.

      I’m very excited about the vehicle. I see it’s potential for my use case, daily commuter.

      I think Joshua has a great idea. They should do a focused presentation on the tech they propose with some ‘potential real life use cases’ to address this question. I know I am not the only one.

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